x-intercept just means the point when the line crosses the x-axis. When the line crosses the x axis, y must be equal to 0. So to find the x-intercept we just take the equation, set y=0, and solve for x.
4x-5y=40
4x-5(0)=40
4x=40
x=10
So the point of interception would be (10,0), or answer A.
